1. Field of the Invention
The present invention relates to an image pickup module on which an image pickup element is mounted, for use in an image pickup apparatus, etc., and to a spacer which has an infrared ray cut film, for use in the image pickup module. The present invention also relates to a method of manufacturing the image pickup module.
2. Description of the Related Art
Various types of products are provided as an image pickup module on which an image pickup element such as a CCD (charge-coupled device) or a CMOS (complementary metal-oxide semiconductor) is mounted (for example, refer to JP-A-2004-147032 and JP-A-2004-235547). FIG. 5 shows an example of an image pickup module configured in such a manner that a light receiving lens 12 is supported by a barrel portion 10a of a holder 10 through a lens holder 11, and that a mounting surface side of a substrate 20, on which an image pickup element 21 is mounted, is accommodated in a casing portion 10b of the holder 10.
This image pickup module is formed as follows. That is, first, an infrared ray cut glass filter 13 is attached to the inner surface of the casing portion 10b so as to seal an opening hole 10c of the barrel portion 10a. Thereafter, the lens holder 11 in which the light receiving lens 12 is mounted is placed into the barrel portion 10a through a spacer 14 made of silicon rubber, by being screwed into the barrel portion 10a (see FIG. 6A). Then, the substrate 20 is bonded to an opening end surface of the casing portion 10b (see FIG. 6B).
The spacer 14 is compressed between an end surface of a stopper portion 10d which is formed on the inner circumferential surface of a base part of the barrel portion 10a and an end surface of the lens holder 11, by screwing and fastening the lens holder 11 to the barrel portion 10a. The spacer 14 has a function of securely holding the lens holder 11 in the barrel portion 10a by preventing the lens holder 11 from turning. Also, the spacer 14 has a function of adjusting a distance between the light receiving lens 12 and the image pickup element 21 to a certain distance by tightening and fixing the lens holder 11 to the barrel portion 10a. 
As described above, the product of image pickup module of the related art having the holder 10 and the substrate 20 is configured in such a manner that the infrared ray cut glass filter 13 is attached to the base part of the barrel portion 10a of the holder 10 (that is, the inner surface side of the casing portion 10b) so as to seal the opening hole 10c. Thus, a process of assembling the image pickup module requires a step of bonding the glass filter 13. Because of the configuration in which the glass filter 13 is attached to the inner surface of the casing portion 10b of the holder 10, it is necessary to assure a space for accommodating the glass filter 13 in the casing portion 10b. Consequently, the problem arises that the miniaturization of the image pickup module is restricted.